But yes I know this, I pluged the left flap into Aux 1 and the Right Flap in the Aux 2.

But I tried pluging the secound elvator in the gear slot, as I don't have no electric gear on this bird yet, and I could not get it to work very well. It seems like the gear channel in the reciver dose not work well as a slave for a second servo.

Mike,
To mix successfully into Gear, you will need to kill the Gear switch input first, either by mixing Gear against Gear or by setting Travel Adjust to zero.
Then pick Mix 5 or 6 to include the trim, and mix from Elevator to Gear - reverse as required.
Should work fine.
Regret I have no info on servo reversers.
Cheers,
Pete